Abstract
We encountered three cases of mediastinal lymph node carcinoma with an unknown primary site. Patient 1 was a 68-year-old male. Chest CT revealed mediastinal lymphadenopathy without any primary site. A mediastinal lymphadenectomy was performed, and the histological diagnosis was poorly differentiated adenocarcinoma. A left lung nodule appeared 7 years after the operation. A resection of the left upper lobe was performed, and the pathological findings were similar to the previous mediastinal lymph node carcinoma. Patient 2 was a 72-year-old male who presented with a chief complaint of hoarseness. CT revealed mediastinal lymphadenopathy without any primary site, and a biopsy of the lymph node was performed. The pathological diagnosis was squamous cell carcinoma, and chemoradiotherapy was performed after surgery. A left lung nodule appeared one year after the operation. Patient 3 was a 71-year-old female in whom right lung carcinoma was suspected, and a resection of right lung with both mediastinal and hilar lymphadenectomy was performed. The pathological findings revealed the primary lung tumor to be squamous cell carcinoma; however, the lymph nodes demonstrated large cell neuroendocrine carcinoma. Surgery may be appropriate for patients presenting with mediastinal lymphadenopathy without any primary site, because a diagnosis is necessary to select the optimal therapy and, moreover, lymphadenectomy might facilitate the complete resection of the lymph node and, thereby, lead to an excellent treatment effect.
